Conventional tampon applicators are constructed to provide a pair of elongated, concentric, telescoping tubes so that the outer tube can carry the tampon's absorbent material, the tampon's "pledget," while the inner tube serves as a plunger for dispensing the pledget.
Currently, commercial tampon applicators are formed from either plastic or paper. Plastic tampon applicators are preferred by many women because of a molded-in grip ring and a petal-shaped forward end which facilitates insertion of the applicator article while retaining and protecting the tampon while in the outer tube. Plastic tampon applicators typically are formed from polyethylene using injection molding.
A convenient place to dispose of a tampon applicator is in a toilet bowl. However, all currently available commercial plastic applicators formed of polyethylene are ill-suited for such disposal. Presently available commercial plastic applicators of polyethylene will flush, but they settle in septic tanks without decomposing. They accumulate on screens in waste-water treatment plants, creating blockages. If the screens do not stop the applicator articles, they can escape into the environment intact, washing up on beaches. Plastic applicators do not always float, so they cannot be skimmed, and they do not settle to the bottom of settling tanks. Consequently, a plastic applicator is needed that is both water dispersible and compostable.
Tampon applicators formed from water-soluble polyvinyl alcohol have been proposed, but such polyvinyl alcohol applicator articles in actual practice have been found to become sticky on contact with moist human tissue. In addition, they tend to be relatively unstable in maintaining their dimensions in humid conditions as found in bathroom environments where tampon applicators are typically stored. These water-soluble polyvinyl alcohol applicator articles can be formed by techniques, such as injection molding, to provide the aforementioned design features of grip ring and front petals, but they can become distorted in humid conditions.
U.S. Pat. No. 3,882,869, issued to Hanke, points out that polyvinyl alcohol articles are unstable in the presence of moisture-laden air, as found in bathroom environments, and the polyvinyl alcohol becomes prematurely sticky when in contact with moist surfaces. The Hanke patent teaches a polyethylene oxide polymer or hydroxypropyl cellulose containing a filler, such as talc.
U.S. Pat. No. 3,724,462, also issued to Hanke, teaches tampon applicators formed of inner and outer tubes made of different water-soluble polymers which are incompatible with one another. This is designed to overcome the problems of tubes fusing or sticking together under high humidity/high temperature conditions.
U.S. Pat. Nos. 3,911,917 and 3,882,196, both issued to Hanke, address a further problem of polyvinyl alcohol in that it suffers from odor, specifically an acetic acid smell.
U.S. Pat. No. 5,002,526, issued to Herring, teaches a tampon applicator prepared from injection moldable or extrudable material of polyvinyl alcohol modified to be self-plasticizing.
The tampon applicators formed from polyvinyl alcohol can provide water dispersibility. However, such applicators, when formulated to provide water dispersibility, are found to become sticky. In addition, the applicators display only limited stability in material and dimensional design for preferred design features, such as a grip ring and front petals.
Consumer demand calls for a quality product in convenience and comfort in feminine care applications. A tampon applicator is currently needed to provide tampon insertion articles or devices which are water dispersible and compostable, yet capable of being fabricated into particular shapes suitable for convenience and comfort in the application. The applicator should have long term stability in humid conditions and should be characterized as substantially nonsticky when contacted by mucous membranes or other moist human tissue.